Cephalopelvic disproportion (CPD) describes a situation in which the baby’s head is too large, or the mother’s pelvis too small for a safe vaginal birth.
True CPD is relatively uncommon, but when it occurs, the baby cannot pass safely through the birth canal despite effective contractions. CPD may lead to prolonged or obstructed labor and often requires delivery by cesarean section.
Sometimes labor appears slow because of the baby’s position rather than true CPD. Healthcare providers consider several factors before making the diagnosis.
QUICK FACT
A large estimated fetal weight does not automatically mean CPD.
COMMONLY CONFUSED WITH
- Failure to progress: a clinical description of inadequate progression of labor; CPD is only one possible contributor.
- Macrosomia: unusually large fetal size, which may increase the risk of difficult delivery but does not by itself establish CPD.
SEE ALSO
